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Nitrogen in higher plants
FieMCrops Research, 34 (1993) 227-237
227
Elsevier Science Publishers B.V., Amsterdam
Book Reviews Nitrogen in Higher Plants. Y.P. Abrol (Editor). Research Studies Press, Taunton, Somerset, UK, 1990, 492 pp. £56.10/US$I 16.15, ISBN 0-86380094-7. This volume is No. 8 in the series "Research Studies in Botany and Related Applied Sciences". It contains 16 chapters, collectively covering the area of nitrate and ammonium acquisition and their assimilation by plants; the transport, synthesis and utilization of nitrogenous compounds in plants; nitrogen remobilization and protein degradation during senescence; nitrogen fixation; and carbon/nitrogen interactions and their relationship to crop yield, These are all important topics, and there was much in the book to hold the reader's attention. Despite this, I found the book to provide uneven reading, enjoying the chapters on "Biochemical and biophysical aspects of nitrate uptake and its regulation" (C.E. Deane D r u m m o n d ) , "The physiology of nitrate uptake" (D.J. Pilbean and E.A. Kirby) and "Synthesis, transport and utilization of translocated solutes of nitrogen" (C.A. Atkins and L. Beevers ), but being much less enthusiastic about "Nitrogen metabolism in cereals", "Bioenergetics of grain protein", "Purification, characterization and immunochemistry of higher plant nitrate reductase" and "Nitrate assimilation and grain yield". A repetitive presentation, with little cross referencing between chapters, contributed to this unevenness. Thus the incorporation of ammonia via the glutamate synthase cycle is considered in four separate chapters (pages 163, 181-183,224-226, and 317-319 ), while the chapter on nitrogen metabolism in cereals was not only written in a repetitive style, but covered particular cereals that had been covered in general elsewhere. As a consequence, I often found myself looking back to other chapters to see how what I was reading differed from, or added to, earlier sections. A better delineation of chapters and a more careful editing for content would have made the book much easier to read. It would also have allowed for the addition of two areas which were noticeably downplayed: the discussion of soil nitrogen and its metabolism, and a more detailed consideration of molecular genetic approaches to N metabolism in plants. I would also have liked a more detailed consideration of the relationship between cereal yield increases and N-fertilizer usage. It seems that the book could also have had a long gestation period, as several of the chapters had no reference later than 1986. I am no expert in this
228
BOOK REVIEWS
area, but felt this was most noticeable in the chapter on nitrate reductase activity, particularly in relation to immunological considerations. Even in the chapter on "The genetics of nitrogen-fixing symbiotic associations", which included a significant number of references from 1987 and 1988, the speed with which this field has developed meant that a number of the review articles cited would have been out of date by the time the book was published. In sum, the book is one which provides some interesting reading, and would be a worthwhile library acquisition, but is not one for which I would pay $116. P.H. G R A H A M
Department of Soil Science University of Minnesota, Twin Cities 1529 Gortner, Avenue St. Paul, Minnesota 55108, USA
The Ecology oflntercropping, J.H. Vandermeer. Cambridge University Press, UK, 237 pp., £ 16.95/US$27.95, ISBN 0-521-34689-4. This book applies key ecological theories to some aspects of intercropping. As the author states quite clearly, this is not a comprehensive review of either ecological theory or intercropping research. The key issue, repeated throughout the book, is the organism-environment interaction. When one component crop of an intercrop modifies the environment of the other negatively so that the growth of the second crop is adversely affected by the first component, this is considered to be 'competition'. On the other hand, when the environment modification is positive and the growth of the second is enhanced by the first component, this is called 'facilitation'. These two principles operate in an intercrop, where the degree of competition and facilitation depends on the growth environment, and can be modified by agronomic manipulation. The general idea of manipulation is to reduce the competition effect (effective utilization of the available niche space) and promote facilitation effect. These two principles are described in detail in two chapters (Chapters 3 and 4), following the Introduction (Chapter 1 ) and description of different ways of measuring intercrop performance (Chapter 2 ). Modification of the effects of competition and facilitation by environment (e.g. insect pests) is discussed fully in Chapter 4. In the next paper, mechanisms of the competitive production principle are explained, describing partitioning of both light and soil resources among component crops. The competition for light was further elaborated for intercrops involving perennial crops in Chapter 7. In Chapter 6 some mechanisms to produce facilitation are discussed, and particular attention is given to the intercrop advantage of one component protecting the other from insect pest attack.
227
Elsevier Science Publishers B.V., Amsterdam
Book Reviews Nitrogen in Higher Plants. Y.P. Abrol (Editor). Research Studies Press, Taunton, Somerset, UK, 1990, 492 pp. £56.10/US$I 16.15, ISBN 0-86380094-7. This volume is No. 8 in the series "Research Studies in Botany and Related Applied Sciences". It contains 16 chapters, collectively covering the area of nitrate and ammonium acquisition and their assimilation by plants; the transport, synthesis and utilization of nitrogenous compounds in plants; nitrogen remobilization and protein degradation during senescence; nitrogen fixation; and carbon/nitrogen interactions and their relationship to crop yield, These are all important topics, and there was much in the book to hold the reader's attention. Despite this, I found the book to provide uneven reading, enjoying the chapters on "Biochemical and biophysical aspects of nitrate uptake and its regulation" (C.E. Deane D r u m m o n d ) , "The physiology of nitrate uptake" (D.J. Pilbean and E.A. Kirby) and "Synthesis, transport and utilization of translocated solutes of nitrogen" (C.A. Atkins and L. Beevers ), but being much less enthusiastic about "Nitrogen metabolism in cereals", "Bioenergetics of grain protein", "Purification, characterization and immunochemistry of higher plant nitrate reductase" and "Nitrate assimilation and grain yield". A repetitive presentation, with little cross referencing between chapters, contributed to this unevenness. Thus the incorporation of ammonia via the glutamate synthase cycle is considered in four separate chapters (pages 163, 181-183,224-226, and 317-319 ), while the chapter on nitrogen metabolism in cereals was not only written in a repetitive style, but covered particular cereals that had been covered in general elsewhere. As a consequence, I often found myself looking back to other chapters to see how what I was reading differed from, or added to, earlier sections. A better delineation of chapters and a more careful editing for content would have made the book much easier to read. It would also have allowed for the addition of two areas which were noticeably downplayed: the discussion of soil nitrogen and its metabolism, and a more detailed consideration of molecular genetic approaches to N metabolism in plants. I would also have liked a more detailed consideration of the relationship between cereal yield increases and N-fertilizer usage. It seems that the book could also have had a long gestation period, as several of the chapters had no reference later than 1986. I am no expert in this
228
BOOK REVIEWS
area, but felt this was most noticeable in the chapter on nitrate reductase activity, particularly in relation to immunological considerations. Even in the chapter on "The genetics of nitrogen-fixing symbiotic associations", which included a significant number of references from 1987 and 1988, the speed with which this field has developed meant that a number of the review articles cited would have been out of date by the time the book was published. In sum, the book is one which provides some interesting reading, and would be a worthwhile library acquisition, but is not one for which I would pay $116. P.H. G R A H A M
Department of Soil Science University of Minnesota, Twin Cities 1529 Gortner, Avenue St. Paul, Minnesota 55108, USA
The Ecology oflntercropping, J.H. Vandermeer. Cambridge University Press, UK, 237 pp., £ 16.95/US$27.95, ISBN 0-521-34689-4. This book applies key ecological theories to some aspects of intercropping. As the author states quite clearly, this is not a comprehensive review of either ecological theory or intercropping research. The key issue, repeated throughout the book, is the organism-environment interaction. When one component crop of an intercrop modifies the environment of the other negatively so that the growth of the second crop is adversely affected by the first component, this is considered to be 'competition'. On the other hand, when the environment modification is positive and the growth of the second is enhanced by the first component, this is called 'facilitation'. These two principles operate in an intercrop, where the degree of competition and facilitation depends on the growth environment, and can be modified by agronomic manipulation. The general idea of manipulation is to reduce the competition effect (effective utilization of the available niche space) and promote facilitation effect. These two principles are described in detail in two chapters (Chapters 3 and 4), following the Introduction (Chapter 1 ) and description of different ways of measuring intercrop performance (Chapter 2 ). Modification of the effects of competition and facilitation by environment (e.g. insect pests) is discussed fully in Chapter 4. In the next paper, mechanisms of the competitive production principle are explained, describing partitioning of both light and soil resources among component crops. The competition for light was further elaborated for intercrops involving perennial crops in Chapter 7. In Chapter 6 some mechanisms to produce facilitation are discussed, and particular attention is given to the intercrop advantage of one component protecting the other from insect pest attack.